Well I ended up with this:
Lovan rack: Top shelf reinforced with steel plate, bonded by wall-damp material. Rest of lovan racks damped with wall damp material, and wall damp material/sorbothane in the rack columns. That really deadened ringing vibration just in the Lovan rack itself.
On top of the Lovan shelf I have: Townshend isolation pods (spring) holding up a sandwich two MDF boards, 1/2" + 3/4", bonded together by wall damp material. Then added a layer of steel (really deadened things), then the 2 1/2" Maple block on top of that, on which sits the Transrotor Turntable.
This means the actual shelf the turntable sits on is very dead and heavy, while also being very well isolated itself from floor-borne extraneous vibration.
I FINALLY hooked up the Turntable last night (with JE Audio Phone Stage) and took a spin of a bunch of records.
Holy moly!
Amazing. High fidelity vinyl playback! Super dark background, liquid presentation, spacious, clear...in some ways the best sound I've heard out of my system. I'm continually astonished at how transformed every record, and recording, is on this system in terms of being able to hear into the mix every nuance so easily. Now I really get what the vinyl guys have been saying :-)